Muffler for internal combustion engine

Abstract

A performance muffler suitable for installation into an exhaust system for an internal combustion engine wherein either end of the muffler may be designated as the entrance end for the receipt of exhaust gases into the muffler without materially altering the functionality of the muffler. A method is disclosed.

1. A muffler for an internal combustion engine having an exhaust, comprising
 a hollow housing having top, bottom and opposite side walls and first and second opposite ends, and a transverse centerplane, 
 a central post of substantially round transverse cross-section disposed within said housing at a location substantially equidistant between said opposite side walls and substantially equidistant said first and second opposite ends of said housing, 
 a first elongated tubular member mounted within said housing adjacent said central post and on that side of said post facing said first end of said housing, said tubular member being bent along its length and with the inside of said bend facing the outer circumference of said central post, 
 a second elongated tubular member mounted within said housing adjacent said central post and on that side of said post facing said second end of said housing, said tubular member being bent along its length and with the inside of said bend facing the outer circumference of said central post, 
 first and second end plates sealingly closing respective ones of said first and second opposite ends of said housing fluid tight, 
 at least one port defined in one of said first and second end plates for establishing fluid flow communication between the interior of said housing and an ambient conduit leading from the exhaust of the engine and 
 at least one port defined in one of said first and second end plates for establishing fluid flow communication between the interior of said housing and the ambient environment. 
 
   
   
     2. The muffler of  claim 1  and further including first and second baffles disposed in spaced apart, substantially parallel, relationship to respective ones of said first and second end plates, each of said baffles including an outer perimeter which is coincident with the inner cross-sectional geometry of said housing whereby each of said baffles is force-fitted within said housing to define a chamber within said housing between each baffle and its respective end plate, said chamber being essentially closed against the inflow of substantial moisture into said chamber. 
   
   
     3. The muffler of  claim 2  wherein each of said baffles includes a port which is in register with a respective one of said at least one port defined in a respective one of said end plates, and including a tubular member inserted through said registered ports to further define a fluid flow passageway between the interior of said housing and the exterior of said housing. 
   
   
     4. The muffler of  claim 3  wherein each of said tubular members projects outwardly of said housing beyond its associated end plate and projects inwardly into the interior of said housing beyond its associated baffle. 
   
   
     5. The muffler of  claim 3  wherein each of said tubular members includes an outward end which terminates substantially flush with the port defined in its associated end plate. 
   
   
     6. The muffler of  claim 1  wherein each of said first and second elongated tubular members includes a first and second end and said first end thereof defines a wedge-shaped opening with a first one of said side walls and said second end defines a wedge-shaped opening with a second one of said side walls, each of said wedge-shaped openings opening toward the transverse centerplane of said housing, said openings providing for the flow of exhaust gases and associated noises into each elongated tubular member. 
   
   
     7. The muffler of  claim 6  wherein each of said first and second ends of each of said elongated tubular members includes a circumferential rim and only a limited portion of said rim of each of said first and second ends of each of said first and second elongated tubular members physically engages a respective side wall and including means anchoring said limited portion to a respective side wall. 
   
   
     8. The muffler of  claim 1  wherein each of said elongated tubular members includes a longitudinal centerline and is bent substantially centrally of the length thereof at an included angle of about 25 degrees relative to the longitudinal centerline of said tube. 
   
   
     9. The muffler of  claim 1  wherein each of said bent elongated tubular members partially wraps said central post. 
   
   
     10. The muffler of  claim 9  wherein each of said bent elongated tubular members is anchored to said central post. 
   
   
     11. The muffler of  claim 1  and further including third and fourth elongated bent tubular members disposed in aligned stacked relationship to said first and second elongated bent tubular members. 
   
   
     12. The muffler of  claim 6  wherein said wedge-shaped openings provide for the entry of exhaust gases and associated noises emanating from the engine to enter said tubular members from opposite ends thereof with resulting modulation or cancellation of at least a portion of said associated noises. 
   
   
     13. The muffler of  claim 1  and further including more than two ports defined in at least one end plate of said housing and including means for sealingly closing at least one of said ports. 
   
   
     14. The muffler of  claim 1  and further including at least three ports defined in each of said first and second end plates of said housing. 
   
   
     15. The muffler of  claim 14  wherein each of said ports is provided with a tubular member having a first end which terminates substantially flush with its respective end plate. 
   
   
     16. A method for modulation of the exhaust gases and noises associated therewith emanating from the exhaust system of an internal combustion engine comprising the steps of
 connecting a muffler in fluid flow relationship to the exhaust system of the engine whereby gases and associated noises emanating from the engine are directed into and through said muffler, 
 within said muffler, subjecting said exhaust gases and associated noises to flow impediments which present only smooth direction-altering surfaces substantially free of abrupt structural changes of flow direction changes to said exhaust gases moving through the muffler, there being not more than three material flow impediments internally of said muffler and further including the step of directing a portion of said exhaust gases into the opposite ends of at least one elongated bent tube whereby noises associated with said gases are modulated or cancelled. 
 
   
   
     17. A muffler in accordance with  claim 1  and including at least one plug suitable for use in closing at least one port in one end plate of said muffler, said muffler and said at least one plug being packaged as a unit.